Misfire or Misfit TD4

Hi Guys

I have a FL TD4 (2001) which had a intermitent misfire on idle my mate who owns a garage plugged it in to his snap-on modis machine which showed no error codes, when the RPM rises from idle it would fire on all 4 cyl and run quite sweet.
He then unpluged the injector one by one and found that one of the injectors was the problem, we have just changed the injector and at the same time removed the EGR valve and replaced it with the bypass valve you can get from *bay etc we cleaned all the oil and goo that clog up the manifold and blocked up the vacuum pipe.

Started up the FL and it fired and ran first key sweet as a nut on idle, but now if you drive it, it misfires and runs on 3cyl with clouds of smoke etc
the grease and oil was removed using rags and a screwdriver (there was no chemicle cleaners used) we ran out of time today and will have another look tomorrow, I thought I would post on here to see if you guys have seen or heard anything like this or have we missed somthing maybe with the EGR bypass valve....

Many Thanks
Evo1970

wouldn't have thought that anything with the EGR could cause it to only run on 3 cylinders under load, I would be looking to the injector you have just changed as this is more likely to cause one cylinder to misfire.

As OP says, the EGR affects all cylinders, not just one. Clouds of white smoke? Thats unburnt fuel. Somethings up in one of cylinders, probably regarding compression. Could be head gasket or a burnt valve. Could also be where you disturbed the wiring. Also check the cam belt hasn't slipped a tooth. Will have a think about this and post if I think of something else.

Re the work just carried out I would concentrate on the inlet manifold for correct sealing and check all air hoses for condition and security. If all this checks out then I would suspect the new injector? Good luck.D..

*Update*

Phew where do I start....

We unplugged the MAF and and all seemed fine low down power no missing, power dropped off around 3000rpm so we changed the MAF and wow it seemed to have sorted it out.
We now know the EGR bypass valve had nothing to do with the problem now, so thanks guys.
But... There is now a whooshing sound like a split or loose pipe from the turbo (not the standard noise that come's with turbos) and now a sudden loss of power lots of black smoke...
Checked all pipes and vacuum pipes for splits etc, nothing found accutator and boost sensor seem to be working fine turbo spins up ok no codes stored in ECU fuel rail working/running at 2.5 bar.

any more ideas on this one guys...:doh:

many thanks
eVo

Definitely sounds like boost pressure escaping. It could also explain the black smoke.
Intercooler hose leaking somewhere, maybe not seated properly even though it appears tight? You may have to remove each one and examine carefully.

Did you remove the inlet manifold to clean it out? If so then you need to check that it is sealing properly! if the inlet manifold does not seal it confuses the whole engine management process including the MAF sensor signals. D..

The manifold was cleaned out and made sure it was reseated correctly, the next step is too take off all hoses and check theres no splits individually, thanks again guys for the support....

Evo1970 said:

The manifold was cleaned out and made sure it was reseated correctly, the next step is too take off all hoses and check theres no splits individually, thanks again guys for the support....

Click to expand...

If you are hearing a whooshing noise there MUST be a big escape of air between the turbo outlet and the cylinder head inlet manifold face.

CharlesY

Darmain said:

Also check the cam belt hasn't slipped a tooth. Will have a think about this and post if I think of something else.

Click to expand...

TD4 doesn't have a belt.
Have you blocked the EGR vcuum pipe?
Wonder if the variable bit of the turbocharger isn't varying properly?

Allan

Yeah.. The vacuum pipe to the EGR valve has been blocked, next job is to remove all hoses and inspect them closely and replace if necessary.